An improved sliding clip for a standing seam roof, the clip having a clip base supporting a clip tab adapted to connect to a standing seam, the clip tab slidably supported by the clip base along a slide track on the clip base, the clip tab permitted to travel a selected range along substantially the full length of the clip base so that the length of the travel path can exceed or be less than the length of the clip base. Stop members on the clip base and clip tab are positioned to abut when the clip tab is moved in either direction along the slide track. Alternate tab stops can be provided to selectively determine the extent of travel of the clip tab along the travel path.